Sergeant major (fish)

Swarm on the coast of Jamaica.

Abudefduf saxatilis is a Riffbarschart, both on the American Atlantic coast between Rhode Iceland (USA) and Uruguay, and also near the West African Atlantic coast south occurs from the Cape Verde Islands to Angola. Particularly common is the type in the coral reefs of the Caribbean.

Together with two other Riffbarscharten abudefduf saxatilis was already described in 1758 by the Swedish naturalist Carl Linnaeus, the founder of the binary nomenclature, in the tenth edition of Systema Naturae of his work, at that time under the name Chaetodon saxatilis.

Features

Abudefduf saxatilis is flattened high backs and sides. Most specimens of the species are 15 cm long, the largest measured length is 22.9 cm, the maximum weight at 200 g The body length is 1.6 to 2.0 times the body height. Young abudefduf saxatilis and the females are greenish on the back side, the body sides and belly are whitish. Five striking, vertical, black stripes, which are narrower toward the abdomen, pattern the fish. A sixth, not always existing strip can be seen on the rear end of the tail fin shaft. A black dot is on the pectoral fin base. Mature males get a dark blue color and the striped pattern is less visible. Because of the stripe pattern, the fish are in English-speaking countries Sergeant Major called because it is reminiscent of the rank insignia of officers. In line with the English name, the name "Striped Sergeant " is used in English.

  • Fins formula: Dorsal XIII/12-13; Anal II/10-12, pectoral 16-20.
  • Dandruff formula: SL 19-23.
  • Gill rakers: 23-31.

Dissemination

The distribution area of abudefduf saxatilis is restricted to the Atlantic Ocean. In the western Atlantic it comes from 41 degrees north latitude off the coast of Canada on the state of Rhode Iceland in the U.S. to Brazil and Uruguay before. In the Caribbean, he is in all reefs, for example, often represent the barrier reef off the coast of Belize.

Abudefduf saxatilis is also found around the islands in the Atlantic, such as Fernando de Noronha off the coast of Brazil or Madeira and the Cape Verde Islands off the coast of West Africa. The distribution area extends far south to Angola on the West African coast.

In the Indo-Pacific abudefduf saxatilis is represented vaigiensis by the closely related species abudefduf, which was formerly often considered a subspecies of abudefduf saxatilis. Through this former definition is often found also the coasts of East Africa and Madagascar, the Seychelles or Mauritius and Reunion islands as home to abudefduf saxatilis in the literature. However, the Indian Ocean and the Red Sea include vaigiensis to the area of ​​distribution of abudefduf.

Way of life

Abudefduf saxatilis riffgebunden lives in coastal rock or coral near the surface to depths of 20 meters. It feeds on algae, small crustaceans, small fish and larvae of various invertebrates. To this end, he is like the doctor fish mostly large feeding flocks of several hundred individuals.

One ectoparasite known this Riffbarsches is Holobomolochus glyphisodontis from the family of copepods.

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